As the Pole Star is always around the North Pole at radius of 1°, so it is always on or near the meridian passage. The latitude of the observer can be determined. The position line runs in an east-west, or nearly east-west direction.
- The obs latitude obtained by an observation of polaris is not necessarily the latitude of the vessel as the PL is nearly E-W not necessarily exactly E-W.
- Polaris cannot be seen from the southern hemispere or from very low latitudes in the northern hemisphere.
Points to pounder for POLARIS method:
In the Northern hemisphere the pole star (Polaris) is almost at the centre of the wheeling circle of stars so to within a degree or so you get due North, once you can spot Polaris.